Bonding in Some Homonuclear Diatomic Molecules

\[\ce{CO}\] is isoelectronic with

(i) \[\ce{NO+}\]

(ii) \[\ce{N2}\]

(iii) \[\ce{Sncl2}\]

(iv) \[\ce{NO^{-}2}\]

Assertion (A): Among the two \[\ce{O - H}\] bonds in \[\ce{H2O}\] molecule, the energy required to break the first \[\ce{O - H}\] bond and the other \[\ce{O - H}\] bond is the same.

Reason (R): This is because the electronic environment around oxygen is the same even after breakage of one \[\ce{O - H}\] bond.

Give reasons for the following:

Ethyne molecule is linear.